Physical activity is associated with reduced risk of mortality and CVD in all regions of the world
The effect of physical activity on mortality and cardiovascular disease in 130 000 people from 17 high-income, middle-income, and low-income countries: the PURE studyLear SA, Hu W, Rangarajan S, et al. - Lancet 2017; published online ahead of print
70% of global CVD deaths come from low- and middle-income countries, where it is the commonest cause of death . Many studies from high-income countries have reported significant inverse associations of physical activity with mortality and CVD morbidity, but there are not enough data on this topic from low- and middle-income countries [2,3].
In this analysis of 130 843 participants in the PURE study, the association between physical activity and the risk of mortality and CVD was evaluated, in countries at varying economic levels. It was also evaluated whether this association differs by type of physical activity.
The PURE study includes 168 916 participants from:
- 3 high- income countries (Canada, Sweden, United Arab Emirates)
- 7 upper-middle-income countries (Argentina, Brazil, Chile, Poland, Turkey, Malaysia, South Africa)
- 3 lower-middle-income countries (China, Colombia, Iran)
- 4 low-income-countries (Bangladesh, India, Pakistan, Zimbabwe)
The 1-week total physical activity was assessed using the long-form International Physical Activity Questionnaire (IPAQ), and calculated as a total of occupation, transportation, housework, and recreational activity reported in metabolic equivalents (MET) × minutes per week .
The total physical activity was categorized as:
- low (<600 MET × minutes per week)
- moderate (600–3000 MET × minutes per week)
- high (>3000 MET × minutes per week)
Physical activity meeting current guidelines is ≥600 MET × minutes per week .
Primary clinical outcomes during follow-up were mortality plus major CVD (CVD mortality plus incident MI, stroke, or HF), either as a composite or separately.
- In fully adjusted models, meeting physical activity guidelines was associated with an HR for mortality plus major CVD of 0.78 (95% CI: 0.74–0.83; P<0.0001), an HR for mortality of 0.72 (95% CI: 0.67–0.77; P<0.0001), and an HR for major CVD of 0.80 (95% CI: 0.74–0.86; P<0.0001).
- In fully adjusted models, moderate and high physical activity were associated with lower HRs for mortality plus major CVD (P<0.0001 for trend), for mortality (P<0.0001 for trend), and for major CVD (P=0.0005 trend) compared with those with low total physical activity.
- Higher physical activity was also associated with lower HRs in CVD mortality, non-CVD mortality, and MI.
- Survival curves for low, moderate, and high physical activity for the 3 primary outcomes of mortality plus major CVD, mortality, and major CVD, indicated a lower risk as physical activity increased (P<0.0001).
- Higher physical activity was associated with significantly lower risk for mortality plus major CVD in upper-middle-income countries and low-income countries, mortality in upper-middle-income countries, lower-middle-income countries, and low-income countries, and major CVD in upper-middle-income countries and low-income countries.
- When stratified by country income level there was a significant interaction between country income level and physical activity for total (P=0.0012) and recreational physical activity (P=0.0063), such that the high-income countries and upper-middle-income countries had a lower risk with increasing physical activity. This was less clear for non-recreational physical activity (P=0.63).
Physical activity is associated with a lower risk for mortality and major CVD events, independently of the type of physical activity and other risk factors, in all major regions of the world and various country economic levels. These results show that physical activity is a global low-cost approach to reducing deaths and CVD, which supports public health interventions to increase all forms of physical activity in countries of different socioeconomic circumstances.
In their editorial article , Goenka and Lee note about the study published by Lear et al: ‘This is another confirmation that physical activity has definite and dose-dependent benefits for lowering risks of all-cause mortality and cardiovascular disease (heart attacks, stroke, and heart failure).’ They emphasize the need to take action to inform people about the benefits of physical activity, particularly in low-income countries, as well as the need to create and emphasize initiatives that will motivate people to undertake more physical activity.
The authors conclude: ‘Promotion of physical activity, active transport, and active living by means of interventions contextualized to culture and context will have powerful and long lasting effects on population health and developmental sustainability.’